Heterotransplantation of human head and neck tumours into nude mice.

Multimodality therapy of advanced malignant tumours of the head and neck includes surgery, radiotherapy and chemotherapy. However, the cure rate for these tumours is low and guidelines for the selection and timing of therapy are needed. For such guidelines, tumour cell kinetic parameter studies, e.g. cell proliferation, may be a suitable approach. In the present study an in vivo system for tumour cell kinetic studies, the nude mice system, has been evaluated for malignant human head and neck tumours. The overall 'take' rate for heterotransplanted human tumour grafts was 35%. The take rate was not influenced by the sterility state of the specimen. An advanced tumour stage showed a tendency to a higher take rate than less advanced tumour stages. In the tumour cell kinetic study the rate of DNA synthesis, measured by incorporation of radioactively labelled thymidine ( [3H]TdR) into DNA, was analysed in human malignant head and neck tumours and in serially heterotransplanted tumours. The rate of DNA synthesis was found to increase during the first serial passages though the histopathological picture remained unchanged. The increased rate of DNA synthesis may be explained by the recruitment of Go cells or by stem cell selection. These findings are discussed and may provide a basis for therapeutic guidelines.